Steam-boiler.



" Patented lan. 2 l, I902.

F. a. & F..H. BATES."

. STEAM BOILER (Application filed Nov. 9, 1896.)

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'Patented Ian. 2r, I902.

F. a. & r. H. BATES.

STEAM BOILER.

(Application filed Nov. 9, 189B.)

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(No Model.)

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UNITED STATES PATENT OFFICE.

FRANCIS G. BATES AND FRANK H. BATES, OF PHILADELPHIA,

PENNSYLVANIA.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 691,580, dated January 21, 1902.

Application filed November 9, 1896- Serial No. 611 ,457. (No model.)

To all whom/it may concern:

Be it known that we, FRANoIs G. BATEs and FRANK H. BA'rEs,citizens of the United States, and residents of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have jointly invented certain new and useful Improvements in Steam-Boilers, of which the following is a specification.

This invention relates generally to watertube boilers, and particularly to upright water-tube boilers.

Figure 1 of the accompanyingdrawings is a front elevation of the preferred construction of our improved boiler. Fig. 2 isa horizontal section on the line 2 2 in Fig. 4. Fig. 3 is a horizontal section on the line 3 3 in Fig. 4.. Fig. 4 is a vertical mid-section. Fig. 5 is a section of one of the upright water-tubes on a larger scale. Fig. 6 is a cross-section of Fig. 5 on the line6 6. Fig. 7i'safragmentary sectional plan showing the connections for introducing fuel-gas to the grate-bars. Fig. 8 is a transverse section through the gratebars, showing the gas-passages therein.

The specific boiler shownin the drawings is designed, primarily, to be heated by combustion of fuel gas, although it may be used for burning solid fuel. The boiler is of that general class wherein a steam-drum above and a mud-drum beneath are connected by water-tubes, the flames or hot gases being arranged to circulate around these tubes.

Let A designate the furnace, and B the grate thereof. The furnace Acommunicates with an upright chamber C, formed by masonry walls lined, preferably, with fire-brick. The steam-boiler proper is inclosed in the chamber G. The boiler is constructed with a steam-drum D, a mud-drum E, and boilertubes F F, extending between them and arranged concentrically, preferably in the manner shown in Fig. 3, where a central space is shown for the free upward circulation of hot gases after the same have passed around and between the tubes. The steam-drum D is formed with a tubular flue G, extending through its central portion and communicating with this space inclosed by the lines. From the flue G leads a flue G, which communicates with a stack or chimney.

The boiler is supported by brackets a a,

bolted to the steam-drum D and resting on a ledge formed in the upper portion of the ma- I sonry shell 0 of the furnace. The mud-drum E is suspended from the steam-drum through the intervention of the tubes F, so that ex pansion or contraction of the tubes is allowed for by a slight rise or fall of the mud-drum. To permit of access being had to the tubes, the steam-drum, D is madein two portions divided horizontally, the upper portion or cap (lettered D) being removable. It is connected to the lower portion bymeans of flanges b and c, riveted to the outer shell and to the tube formingthe flue G, respectively. For reaching these inner flanges in order to tighten the bolts connecting them a manhole d, Fig. 2, is provided, which is reached through a door e, closing an opening in the outer masonry. The upper portion of the steam drum projects into a chamber 0, formed within the masonryO andcovered by a cap 11, which'may or may not be cast intogrally with the flue G. The cap H may be removed, taking the flue G with it, to gain access to the chamber 0. For taking off the cap D the bolts of the outer flanges b are accessible from this chamber.

The feed-pipe I enters laterally into the lowerportion of the steam-drum beneath the waterline and preferably curves around therein, as shown in Fig. 2. The steam-pipes J J (one or more) lead, preferably, from the cap D of the steam-drum, as shown. As the circulation in the water-tubes F is upward, a downflow-pipe K is provided, extending, preferably, exterior to the masonry wall 0, for taking the water from one sideof the steam-drum D and delivering it into the muddrum E. A blow-off pipe L is provided, leading from the bottom of the mud-drum and normally closed by a valve f. For cleaning the mud-drum a manhole d is provided in its bottom, closed in the usual way.

A water-column M and water gage or tube N are arranged outside the masonryand connected byhorizontaltubes to the drum D,these tubes being arranged, respectively, above and below the extreme variations of waterlevel. The water-column M has gage-cocks, as usual, for determining the Water-level.

The flames from the fuel in furnace A pass over the bridge and into the upright chamber containing the tubes F, and the flames and hot gases circulate around these tubes, heating the water therein, the hot products of combustion finally escaping by the dues G G to the stack. The water in the tubes is heated and circulates upwardly, the cooler water in the drum above flowing downward by the pipe K to the lower drum, whereby a circulation is maintained.

For burning fuel-gas in the furnace the grate B is made up of bars which are cast with gas-passages traversing them longitudinally, as shown in transverse section in Fig. 8. Small holes are drilled at intervals through the top of each bar, communicating with these passages, so that the gas may issue 1 from these holes and be ignited above the grate-bars.

mit of disconnecting any grate-bar independently of the other. The supply of air for maintaining combustion can be introduced through dampers in doors it it, which open beneath the grate into the ash pit or chamber Z. Air may also be admitted through a damper in a door m, communicating with the combustion chamber or space above the grate. In a furnace burning solid fuel the door m becomes the charging-door and the doors 7c the ash-doors. Air may be admitted in admixture with the gas, if desired, as in any ordinary Bunsen burner.

An important feature of our invention is shown best in Figs. 5 and '5. These figures show one of the water-tubes F, having suspended within it a heat-retaining core Q. This core is extended longitudinally of the tube for preferably its entire length and is arranged concentrically within it, so that the water in the tube is divided into an annular or tubular column, the center of which is occupied by the core Q. It results that the layer of water coming against the wall of thetube is reduced in thickness to an extent varying according to the greater or less diameter of the core Q in proportion to the diameter of the water-tube. By relatively increasing the diameter of the core the water may be reduced to a comparatively thin stratum or layer. Theresult is that the water is more rapidly heated than if the core were absent, so that the boiler has a greatly-increased capacity for quickly generating steam. Another important function of the core lies in its capacity for absorbing and storing heat. To this end we make the core of a heat-absorbent material, preferably constructing it of a somewhat thin metal tube filled with any suitable heat-retaining material, preferably a mortar of lime and sand. The cores arranged in the numerous boiler-tubes have thus a considerable aggregated heat-storing capacity.

The gas enters through a pipe P into a transverse pipe or header h, as shown such heat-retaining cores is to equalize the heating effect upon the columns of water, since whenever the exterior source of heat is discontinued or reduced, so that the water tends to cool, the cores commence giving out heat to the water, so that they keep up the temperature of the water for a time above what it would otherwise be, and hence the steam-generating action of the boiler continues with greater uniformity under variations in the source of heat than would be the case in a boiler of ordinary construction. This is especially desirable in boilers heated by gas derived from local fuel-gas plants, since at times it becomes necessary to wholly or partially suspend the introduction of gas for a few minutes, and in such case the steam-pressure is maintained with less diminution than would be the case if the heat-retaining cores were not used. This feature of our invention is applicable in connection with any construction of water-tube boiler, whether the tubes extend vertically or otherwise, but is most effective in connection with upright tubes or inclined tubes which approximate to an upright arrangement.

For supporting the cores and holding them concentrically each core is provided with a spider p, screwed or fastened on its upper end,and having, preferably, three arms which extend downwardly, overlying the upper end of the tube F and also extending down within it for a short distance, as clearly shown in Fig. 5. Another spider q is arranged for holding the lower end of the tube concentric,

this spider, however, consisting merely of arms projecting outwardly and lying loosely against the inner walls of the tube. These spiders may form caps for closing the outer ends of the tube, as with the construction of spider q shown, or a separate cap maybe applied exterior to the spider, as is shown at 4'.

What we claim isl. A water-tube boiler having its tubes provided with heat absorbent cores arranged within them and means for holding the cores separated from the tubes so as to leave an annular space between the tube and core for circulation of water, such cores constructed as tubes inclosing a heat-absorbent material.

A water-tube boiler having its tubes provided with heat-absorbent cores within them, said cores constructed as a sealed metal tube with a filling of heat-retaining mortar.

In a boiler, a vertical water-tube combined with a concentric core-tube within it, having a centering spider at its bottom engaging the inner surface of the water-tube, and having at its top a suspending-spider having arms overlying and projecting within the water-tube to support and center the coretube, all adapted to permit the core to be drawn out upwardly.

An upright tubular boiler comprising an annular steam-drum D, a mud-drum E, and intervening tubes F F, an upright cham- The practical effect of the use of it her inclosing the tubes, a furnace commu- IIO nicating with the bottom of said chamber, a flue through saidannular drum, and a downfiow-pipe K exterior to said chamber leading from the steam-drum below the water-level to the mud-drum. I

5. A boiler comprising a steam-drum D, mud-drum E, and intervening upright watertubes F F, the steam-drum constructed with supported upon the wall of said chamber, Water-tubes F F, and mud-drum E, suspended from said steam-drum, cap H covering the top of said walll and forming a chamber 0 inclosing the upper vportion of the steamdrum, and lines G and G formed respectively through said steam-drum and chamber 0.

In testimony whereof we have hereunto signed our namesin the presence of two subscribing witnesses.

FRANCIS o. BATES. FRANK H. BATES.

Witnesses:

FRANCIS J. SOANLON JOHN J. MINNICK. 

